<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <meta http-equiv="X-UA-Compatible" content="ie=edge">
    <title>Document</title>
</head>
<body>
    <script>
        // 1.声明数组
    var arr=["html","css","javascript"];
    // 2.读取数组中的值，听过下表去读取
    console.log(arr[0])
    console.log(arr[2])
    // 3.length 通过这个属性可以获取数组的长度
    var length=arr.length
    console.log(length);
    // 4.读取数组最后一个元素的值
    var lastChild=arr[arr.length-1];
    console.log(lastChild)
    </script>
    
</body>
</html>